Thomson first, by a long way. Robert William Thomson, a Scot aged twenty-three, was granted British patent GB 10,990 on 10 December 1845 for what he called the "Aerial Wheel": a hollow leather outer enclosing a rubberised fabric tube filled with air. He demonstrated them in Regent's Park in 1847, where they measurably reduced noise and improved comfort on horse-drawn carriages. They worked. They also cost a fortune, because natural rubber was scarce and expensive in the 1840s, and there was no mass market for a smoother carriage ride. The patent lapsed into obscurity and Thomson moved on — he also invented a fountain pen.

Dunlop second, and invalidated. John Boyd Dunlop, a Belfast vet, made an air tyre in 1888 for his son's tricycle and applied for a patent on 23 July 1888, granted as GB 10,607 that December. It was later declared invalid on the grounds of Thomson's prior patent. What Dunlop had that Thomson lacked was timing: the safety bicycle had just arrived, cycling was a mass craze, and vulcanised rubber was cheap. The company that bore his name succeeded even though the patent did not. Describing Dunlop as the inventor of the pneumatic tyre is simply incorrect, and the record is unambiguous.

Why air beats every solid. Compressed air is very nearly a perfect spring: it stores energy when compressed and returns almost all of it when it expands, losing little to internal friction. A solid elastomer soft enough to absorb a bump converts a large fraction of that energy to heat, which is both lost work and a route to failure. Because a pneumatic tyre carries load by pressure, its contact patch area is approximately the load divided by the inflation pressure — a relationship that holds remarkably well and explains why pressure, not rubber compound, is the first thing to check.

The part that took longest. Neither patent solved the real obstacle to adoption: repairing a puncture. Early tyres were cemented or lashed to the rim and had to be cut off. The detachable, repairable tyre came from Édouard and André Michelin in 1891, and the beaded-edge rim that lets a tyre be levered off followed. A tyre you cannot mend at the roadside is a laboratory curiosity, which is a fair summary of the first forty-six years of this invention.

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Pneumatic Tyre

Draisine